Dutch iris will come back. I rarely see a mum again, but I hear if you choose special varieties they will make a nice addition to the garden. I have a cat, and I am all frosted over today.

:)

I don't know about dutch iris - they aren't hardy here, but there are winter hardy chrysanthemums that come back every year. I have three kinds: a copper colored very double one that is blooming now right through heavy frosts and freezes, a pink daisy-like one that bloomed about a month ago, and a white daisy-like one that is low-growing called C. weyrichii 'White Bomb' that makes a good groundcover. All spread to one degree or another, mostly more rather than less. I've never had a problem with any of them getting their roots eaten, even in beds with many mice/vole/chipmunk tunnels. They have a rather strong odor, and this may be a discouragement to those that would eat them, or it may just be that they grow faster then they get eaten. I'm planning to dig up my chrysanthemums and then replant them surrounded by a barrier to better restrict their growth.

By the way, moles aren't ever a direct problem with your plants as they eat insects, grubs, and worms. Their tunnels may be used by mice, however, who will eat plants. Voles are shallow tunnelers who eat plants, and in the winter can be quite destructive to plant roots.

nhbabs brings up an interesting point; that she hasn't had a problem with chrysanthemum roots being eaten by pests. Pyrethrins are a natural insecticide produced by some chrysanthemum flowers and pyrethroids are included in many commercially available insecticides. There are some claims that pyrethroids are irritating or harmful to humans if misused, and it could be that critters avoid the roots as being poisonous. This makes me wonder if chrysanthemums could be judiciously planted to deter voles and chipmunks. Just a thought.

As to winter-hardy mums, there are many that will live quite happily year round if they're planted in the spring so they get well-established before it gets cold and nasty. Bluestone Perennials sells many types at reasonable prices, and many GW members, including me, have had good luck with these.

Claire

Just to expand, and perhaps clarify points that others have mentioned about the mums. The varieties sold everywhere in New England in the fall were not most likely not selected and grown with the idea of winter hardiness in mind.

I also grow mums and voles. They both survive!

I have the perennial type mums (clara curtis, mary stoker) that spread a bit too readily. I also have several of the fall "hardy" mums sold in the fall everywhere all pinched and clipped. Some of them come back if you're lucky.

And now that Claire mentions it, one of those patches of mums is in a super high traffic area of vole activity (4' accent boulder vole condo). The mums there are 2-3 years old.

I've never tried dutch iris, unless you mean Iris reticulata, the real early tiny ones. They didn't survive, but I can't tell you why not.